Inbred corn line PHK46

ABSTRACT

According to the invention, there is provided an inbred corn line, designated PHK46. This invention thus relates to the plants and seeds of inbred corn line PHK46 and to methods for producing a corn plant produced by crossing the inbred line PHK46 with itself or with another corn plant. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line PHK46 with another corn line or plant and to crosses with related species.

This application is a continuation of prior application Ser. No. 08/078,804, filed Jun. 16, 1993, now abandoned, which was a continuation of prior application Ser. No. 07/542,335, filed Jun. 1, 1990, now abandoned.

FIELD OF THE INVENTION

This invention is in the field of corn breeding, specifically relating to an inbred corn line designated PHK46.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety/hybrid various desirable traits. For field crops, these traits may include resistance to diseases and insects, tolerance to heat and drought, reducing the time to crop maturity, greater yield, and better agronomic quality. With mechanical harvesting of many crops, uniformity of plant characteristics such as germination and stand establishment, growth rate, maturity, and fruit size, is important.

Field crops are bred through techniques that take advantage of the plant's method of pollination. A plant is self-pollinated if pollen from one flower is transferred to the same or another flower of the same plant. A plant is cross-pollinated if the pollen comes from a flower on a different plant.

Plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny. A cross between two homozygous lines produce a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants each heterozygous at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform.

Corn plants (Zea mays L.) can be bred by both selfpollination and cross-pollination techniques. Corn has separate male and female flowers on the same plant, located on the tassel and the ear, respectively. Natural pollination occurs in corn when wind blows pollen from the tassels to the silks that protrude from the tops of the incipient ears.

The development of corn hybrids requires the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine the genetic backgrounds from two or more inbred lines or various other broad-based sources into breeding pools from which new inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which of those have commercial potential.

Pedigree breeding starts with the crossing of two genotypes, each of which may have one or more desirable characteristics that is lacking in the other or which complement the other. If the two original parents do not provide all of the desired characteristics, other sources can be included in the breeding population. In the pedigree method, superior plants are selfed and selected in successive generations. In the succeeding generations the heterozygous condition gives way to homogeneous lines as a result of self-pollination and selection. Typically in the pedigree method of breeding five or more generations of selfing and selection is practiced: F₁ →F₂ ; F₂ →F₃ ; F₃ →F₄ ; F₄ →F₅, etc.

Backcrossing can be used to improve an inbred line. Backcrossing transfers a specific desirable trait from one inbred or source to an inbred that lacks that trait. This can be accomplished for example by first crossing a superior inbred (A) (recurrent parent) to a donor inbred (nonrecurrent parent), which carries the appropriate gene(s) for the trait in question. The progeny of this cross is then mated back to the superior recurrent parent (A) followed by selection in the resultant progeny for the desired trait to be transferred from the non-recurrent parent. After five or more backcross generations with selection for the desired trait, the progeny will be heterozygous for loci controlling the characteristic being transferred, but will be like the superior parent for most or almost all other genes. The last backcross generation would be selfed to give pure breeding progeny for the gene(s) being transferred.

A single cross hybrid corn variety is the cross of two inbred lines, each of which has a genotype which complements the genotype of the other. The hybrid progeny of the first generation is designated F₁. In the development of hybrids only the F₁ hybrid plants are sought. Preferred F₁ hybrids are more vigorous than their inbred parents. This hybrid vigor, or heterosis, can be manifested in many polygenic traits, including increased vegetative growth and increased yield.

The development of a hybrid corn variety involves three steps: (1) the selection of plants from various germplasm pools; (2) the selling of the selected plants for several generations to produce a series of inbred lines, which, although different from each other, each breed true and are highly uniform; and (3) crossing the selected inbred lines with unrelated inbred lines to produce the hybrid progeny (F₁). During the inbreeding process in corn, the vigor of the lines decreases. Vigor is restored when two unrelated inbred lines are crossed to produce the hybrid progeny (F₁). An important consequence of the homozygosity and homogeneity of the inbred lines is that the hybrid between any two inbreds will always be the same. Once the inbreds that give a superior hybrid have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parents is maintained.

A single cross hybrid is produced when two inbred lines are crossed to produce the F₁ progeny. A double cross hybrid is produced from four inbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybrids are crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁ hybrids is lost in the next generation (F₂). Consequently, seed from hybrid varieties is not used for planting stock.

Corn is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop high-yielding corn hybrids that are agronomically sound based on stable inbred lines. The reasons for this goal are obvious: to maximize the amount of grain produced with the inputs used and minimize susceptibility to environmental stresses. To accomplish this goal, the corn breeder must select and develop superior inbred parental lines for producing hybrids. This requires identification and selection of genetically unique individuals which in a segregating population occur as the result of a combination of crossover events plus the independent assortment of specific combinations of alleles at many gene loci which results in specific genotypes. Based on the number of segregating genes, the frequency of occurrence of an individual with a specific genotype is less than 1 in 10,000. Thus, even if the entire genotype of the parents has been characterized and the desired genotype is known, only a few if any individuals having the desired genotype may be found in a large F₂ or S₀ population. Typically, however, the genotype of neither the parents nor the desired genotype is known in any detail.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred corn line, designated PHK46. This invention thus relates to the seeds of inbred corn line PHK46, to the plants of inbred corn line PHK46, and to methods for producing a corn plant produced by crossing the inbred line PHK46 with itself or another corn line. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line PHK46 with another corn line or a related species.

DEFINITIONS

In the description and examples that follow, a number of terms are used herein. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:

ABS=absolute measurement and % MN is percentage of mean of the experiments in which inbred or hybrid was grown unless otherwise defined.

BAR PLT=BARREN PLANTS. This is the percent of plants per plot that were not barren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near the time of pollination, and is an indication of whether a hybrid or inbred would snap or break near the time of flowering under severe winds. Data are presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Actual yield of the grain at harvest adjusted to 15.5% moisture. ABS is in absolute terms and % MN is percent of the mean for the experiments in which the inbred or hybrid was grown.

CLD TST=COLD TEST. This is the percentage of kernels that germinate under cold soil conditions.

COB SC=COB SCORE. The cob score is a rating of how well the grain is shelled off the cob and how badly the cob is broken up going through the combine. This is given as a 1 to 9 score with 9 being very good. A high score indicates that the grain shells off of the cob well, and the cob does not break.

DRP EAR=DROPPED EARS. This is a measure of the number of dropped ears per plot and represents the percentage of plants that did not drop ears prior to harvest.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to the top developed ear node attachment and is measured in inches.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher the rating the larger the ear size.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishment in the spring and represents the number of plants that emerge on a per plot basis for the inbred or hybrid.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heat units required for an inbred line or hybrid to have approximately 50 percent of the plants shedding pollen and is measured from the time of planting. Growing degree units are calculated by the Barger Method, where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimum temperature used is 50° F. For each inbred or hybrid it takes a certain number of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for an inbred line or hybrid to have approximately 50 percent of the plants with silk emergence from time of planting. Growing degree units are calculated by the Barger Method as given in GDU SHD definition.

GRN QUL=GRAIN QUALITY. This is a 1 to 9 rating for the general quality of the shelled grain as it is harvested based on such factors as the color of the harvested grain, any mold on the grain, and any cracked grain. High scores indicate good grain quality.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture of the grain at harvest.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant from the ground to the tip of the tassel in inches.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount of pollen shed. The higher the score the more pollen shed.

PRM=PREDICTED RM. This trait, predicted relative maturity (RM), is based on the harvest moisture of the grain. The relative maturity rating is based on a known set of checks and utilizes standard linear regression analyses and is referred to as the Minnesota Relative Maturity Rating System.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that do not root lodge; plants that lean from the vertical axis at an approximately 30° angle or greater would be counted as root lodged.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount of scatter grain (lack of pollination or kernel abortion) on the ear. The higher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amount of vegetative growth after emergence at the seedling stage (approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure of the hybrid's worth based on information for up to five traits. A corn breeder may utilize his or her own set of traits for the selection index. One of the traits that is almost always included is yield. The selection index data presented in the tables represent the mean value averaged across testing stations.

STA GRN=STAY GREEN. Stay green is the measure of plant health near the time of black layer formation (physiological maturity). A high score indicates better late-season plant health.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plants per plot.

STK LDG=STALK LODGING. This is the percentage of plants that did not stalk lodge (stalk breakage) as measured by either natural lodging or pushing the stalks and determining the percentage of plants that break below the ear.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure the degree of blasting (necrosis due to heat stress) of the tassel at time of flowering. A 1 would indicate a very high level of blasting at time of flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate the relative size of the tassel. The higher the rating the larger the tassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams) just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate the relative hardness (smoothness of crown) of mature grain. A 1 would be very soft (extreme dent) while a 9 would be very hard (flinty or very smooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that could possibly shed pollen was taken. Data is given as percentage of tillers: number of tillers per plot divided by number of plants per plot.

TST WT=TEST WEIGHT UNADJUSTED. The measure of the weight of the grain in pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain in pounds for a given volume (bushel) adjusted for percent moisture.

YLD=YIELD. It is the same as BU ACR ABS.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relative rating for yield based on plot ear piles. The higher the rating the greater visual yield appearance.

MDM CPX=Maize Dwarf Mosaic Complex (MDMV=Maize Dwarf Mosaic Virus & MCDV=Maize Chlorotic Dwarf Virus): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

COM SMT=Common Smut (Ustilago maydis): Percentage of plants that did not have infection.

SLF BLT=Southern Leaf Blight (Bipolaris maydis, Helminthosporium maydis): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

NLF BLT=Northern Leaf Blight (Exserohilum turcicum, H. turcicum): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

COM RST=Common Rust (Puccinia sorghi): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

EYE SPT=Eyespot (Kabatiella zeae): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

STW WLT=Stewart's Wilt (Erwinia stewartii): Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant.

HD SMT=Head Smut (Sphacelotheca reiliana): Percentage of plants that did not have infection.

EAR MLD=General Ear Mold: Visual rating (1-9 score) where a "1" is very susceptible and a "9" is very resistant. This is based on overall rating for ear mold of mature ears without determining specific mold organism, and may not be predictive for a specific ear mold.

ECB DPE=Dropped ears due to European Corn Borer (Ostrinia nubilalis): Percentage of plants that did not drop ears under second brood corn borer infestation.

ECB 2SC=European Corn Borer Second Brood (Ostrinia nubilalis): Visual rating (1-9 score) of post flowering damage due to infestation by European Corn Borer. A "1" is very susceptible and a "9" is very resistant.

ECB 1LF=European Corn Borer First Brood (Ostrinia nubilalis): Visual rating (1-9 score) of pre-flowering leaf feeding by European Corn Borer. A "1" is very susceptible and a "9" is very resistant.

DETAILED DESCRIPTION OF THE INVENTION

Inbred corn line PHK46 is a yellow, dent corn inbred. PHK46 is best adapted to the southern part of the United States. The inbred can be used to produce hybrids from approximately 124-136 relative maturity based on the Minnesota Relative Maturity Rating System for harvest moisture of grain. PHK46 can be characterized as a high yielding, late, disease tolerant inbred. It is tolerant to both northern and southern corn leaf blight as well as to several other agronomically important diseases.

The inbred has shown uniformity and stability within the limits of environmental influence for all the traits as described in the Variety Description Information (Table 1) that follows. Most of the data in the Variety Description Information was collected at Johnston, Iowa. The inbred has been self-pollinated and ear-rowed a sufficient number of generations with careful attention paid to uniformity of plant type to ensure homozygosity and phenotypic stability. The line has been increased both by hand and in isolated fields with continued observation for uniformity. No variant traits have been observed or are expected in PHK46.

Inbred corn line PHK46, being substantially homozygous, can be reproduced by planting seeds of the line, growing the resulting corn plants under self-pollinating or sib-pollinating conditions with adequate isolations, and harvesting the resulting seed, using techniques familiar to the agricultural arts.

                  TABLE 1                                                          ______________________________________                                         VARIETY DESCRIPTION INFORMATION                                                INBRED = PHK46                                                                 ______________________________________                                         Type: Dent         Region Best Adapted: South                                  A.  Maturity: Average across maturity zones.                                       Zone: 0                                                                        Heat Unit Shed: 1630                                                           Heat Unit Silk: 1660                                                           No. Reps: 33                                                                   HEAT UNITS =                                                                ##STR1##                                                                      *If maximum is greater than 86 degrees fahrenheit, then 86 is used             and if minimum is less than 50, then 50 is used. Heat units accumu-            lated daily and can not be less than 0.                                        B.  Plant Characteristics:                                                         Plant height (to tassel tip): 236 cm                                           Length of top ear internode: 15 cm                                             Number of ears per stalk: Single                                               Ear height (to base of top ear): 84 cm                                         Number of tillers: None                                                        Cytoplasm type: Normal                                                     C.  Leaf:                                                                          Color: (WF9) Medium Green                                                      Angle from Stalk: <30 degrees                                                  Marginal Waves: (OH7L) Many                                                    Number of Leaves (mature plants): 20                                           Sheath Pubescence: (W22) Light                                                 Longitudinal Creases: (PA11) Many                                              Length (Ear node leaf): 86 cm                                                  Width (widest point, ear node leaf): 8 cm                                  D.  Tassel:                                                                        Number lateral branches: 8                                                     Branch Angle from central spike: >45 degrees                                   Pollen Shed: Medium based on Pollen Yield Test                                 (95% of experiment means)                                                      Peduncle Length (top leaf to basal branches): 24 cm                            Anther Color: Green                                                            Glume Color: Green                                                         E.  Ear (Husked Ear Data Except When Stated Otherwise):                            Length: 15 cm                                                                  Weight: 71 gm                                                                  Mid-point Diameter: 39 mm                                                      Silk Color: Pink                                                               Husk Extension (Harvest stage): Medium (Barely Covering                        Ear)                                                                           Husk Leaf: Short (<8 cm)                                                       Taper of Ear: Slight                                                           Position of Shank (dry husks): Pendent                                         Kernel Rows: Straight, Distinct Number = 16                                    Husk Color (fresh): Light Green                                                Husk Color (dry): Buff                                                         Shank Length: 13 cm                                                            Shank (No. of internodes): 8                                               F.  Kernel (Dried):                                                                Size (from ear mid-point)                                                      Length: 10 mm                                                                  Width: 8 mm                                                                    Thick: 4 mm                                                                    Shape Grade (% rounds): 20-40 (36% medium round based                          on Parent Test Data)                                                           Pericarp Color: Colorless                                                      Aleurone Color: Homozygous Yellow                                              Endosperm Color: Yellow                                                        Endosperm Type: Normal Starch                                                  Gm Wt/100 Seeds (unsized): 18 gm                                           G.  Cob:                                                                           Diameter at mid-point: 27 mm                                                   Strength: Strong                                                               Color: White                                                               H.  Diseases:                                                                      Corn Lethal Necrosis (MCMV = Maize Chlorotic Mottle                            Virus and MDMV = Maize Dwarf Mosaic Virus): Inter-                             mediate Maize Dwarf Mosaic Complex (MDMV &                                     MCDV = Maize Dwarf Virus): Intermediate                                        Anthracnose Stalk Rot (C. graminicola): Resistant                              S. Leaf Blight (H. maydis): Resistant                                          N. Leaf Blight (H. turcicum): Resistant                                        Gray Leaf Spot (C. zeae): Intermediate                                         Stewart's Wilt (E. stewartii): Resistant                                       Common Smut (U. maydis): Highly Resistant                                      Head Smut (S. reiliana): Susceptible                                           Fusarium Ear Mold (F. moniliforme): Susceptible                            I.  Insects:                                                                       European Corn Borer-1 Leaf Damage (Pre-flowering):                             Resistant                                                                      European Corn Borer-2 (Post-flowering): Susceptible                            The above descriptions are based on a scale of 1-9, 1 being                    highly susceptible, 9 being highly resistant.                                  S (Susceptible): Would generally represent a score of 1-3.                     I (Intermediate): Would generally represent a score of 4-5.                    R (Resistant): Would generally represent a score of 6-7.                       H (Highly Resistant): Would generally represent a score of                     8-9. Highly resistant does not imply the inbred is immune.                 J.  Variety Most Closely Resembling:                                           Character Inbred                                                               Maturity  PHP60                                                                Usage     PHP60                                                                ______________________________________                                    

Data for Items B, C, D, E, F, and G is based primarily on a maximum of two reps from Johnston, Iowa grown in 1988, plus description information from the maintaining station.

ELECTROPHORESIS RESULTS Isozyme Genotypes for PHK46

Isozyme data were generated for inbred corn line PHK46 according to the procedures described in Stuber, C. W., Wendel, J. F., Goodman, M. M., and Smith, J. S. C., "Techniques and Scoring Procedures for Starch Gel Electrophoresis of Enzymes from Maize (Zea mays L.)", Technical Bulletin No. 286, North Carolina Agricultural Research Service, North Carolina State University, Raleigh, N.C. (1988).

The data in Table 2 compares PHK46 with its parents PHG65 and PH207.

                  TABLE 2                                                          ______________________________________                                         ELECTROPHORESIS RESULTS FOR PHK46                                              AND ITS PARENTS PHG65 AND PH207                                                                 PARENTS                                                       Loci     PHK46         PHG65   PH207                                           ______________________________________                                         ACP1     4             2       2                                               ADH1     4             4       4                                               CAT3     9             9       9                                               DIA1     12            12      8                                               GOT1     4             4       4                                               GOT2     4             4       4                                               GOT3     4             4       4                                               IDH1     4             4       4                                               IDH2     6             4       6                                               MDH1     6             6       6                                               MDH2     3.5           3       3.5                                             MDH3     16            16      16                                              MDH4     12            12      12                                              MDH5     12            12      12                                              MMM      4             4       4                                               PGM1     9             9       9                                               PGM2     4             4       4                                               PGD1     3.8           3.8     3.8                                             PGD2     5             5       5                                               PHI1     4             4       4                                               ______________________________________                                    

INDUSTRIAL APPLICABILITY

This invention also is directed to methods for producing a corn plant by crossing a first parent corn plant with a second parent corn plant wherein the first or second parent corn plant is an inbred corn plant from the line PHK46. Further, both first and second parent corn plants can come from the inbred corn line PHK46. Thus, any such methods using the inbred corn line PHK46 are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like. All plants produced using inbred corn line PHK46 as a parent are within the scope of this invention. Advantageously, the inbred corn line is used in crosses with other, different, corn inbreds to produce first generation (F₁) corn hybrid seeds and plants with superior characteristics.

As used herein, the terms "plant and plant parts" include plant cells, plant protoplasts, plant cell tissue culture from which corn plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as embryos, pollen, flowers, kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk and the like.

Tissue culture of corn is described in European Patent Application, publication 160,390, incorporated herein by reference. Corn tissue culture procedures are also described in Green and Rhodes, "Plant Regeneration in Tissue Culture of Maize," Maize for Biological Research (Plant Molecular Biology Association, Charlottsville, Virginia 1982, at 367-372). Thus, another aspect of this invention is to provide cells which upon growth and differentiation produce the inbred line PHK46.

The utility of inbred line PHK46 also extends to crosses with other species. Commonly, suitable species will be of the family Graminaceae, and especially of the genera Zea, Tripsacum, Coix, Schlerachne, Polytoca, Chionachne, and Trilobachne, of the tribe Maydeae. Of these, Zea and Tripsacum, are most preferred. Potentially suitable for crosses with PHK46 may be the various varieties of grain sorghum, Sorghum bicolor (L.) Moench.

Corn is used as human food, livestock feed, and as raw material in industry. The food uses of corn, in addition to human consumption of corn kernels, include both products of dry- and wet-milling industries. The principal products of corn dry milling are grits, meal and flour. The corn wet-milling industry can provide corn starch, corn syrups, and dextrose for food use. Corn oil is recovered from corn germ, which is a by-product of both dry- and wet-milling industries.

Corn, including both grain and non-grain portions of the plant, is also used extensively as livestock feed, primarily for beef cattle, dairy cattle, hogs, and poultry.

Industrial uses of corn are mainly from corn starch from the wet-milling industry and corn flour from the dry-milling industry. The industrial applications of corn starch and flour are based on functional properties, such as viscosity, film formation, adhesive properties, and ability to suspend particles. The corn starch and flour have application in the paper and textile industries. Other industrial uses include applications in adhesives, building materials, foundry binders, laundry starches, explosives, oil-well muds, and other mining applications.

Plant parts other than the grain of corn are also used in industry. Stalks and husks are made into paper and wallboard and cobs are used for fuel and to make charcoal.

The seed of inbred corn line PHK46, the plant produced from the inbred seed, the hybrid corn plant produced from the crossing of the inbred, hybrid seed, and various parts of the hybrid corn plant can be utilized for human food, livestock feed, and as a raw material in industry.

EXAMPLE INBRED AND HYBRID PERFORMANCE OF PHK46

In the examples that follow the traits and characteristics of inbred corn line PHK46 are given as a line and in hybrid combination. The data collected on inbred corn line PHK46 is presented for the key characteristics and traits.

The results in Table 3A compare PHK46 to PHG65, a parent. In relationship to this parent, PHK46 yields similarly and flowers (GDU SHD and GDU SLK) earlier. PHK46 is shorter but has a slightly higher ear placement than PHG65. PHK46 has better early vigor and higher early stand count than PHG65. PHK46 has better root lodging, common rust, and southern corn leaf blight resistance but is more susceptible to ear mold than PHG65.

The results in Table 3B show PHK46 yields more and flowers (GDU SHD and GDU SLK) later than its parent, PH207. PHK46 is taller with higher ear placement than PH207. PHK46 has better stay green and is more tolerant to diseases and first brood European corn borer than PH207.

Table 3C shows PHK46 yields more, has higher test weight, and less grain moisture at maturity than PHJ31. PHK46 has similar plant height but ear placement is higher and it flowers (GDU SHD and GDU SLK) earlier than PHJ31. The PHK46 inbred has better stalk lodging, common rust, and southern corn leaf blight resistance but is more susceptible to ear mold and first brood European corn borer than PHJ31.

In Table 3D, the results show PHK46 is higher yielding, lower in test weight, and contains more grain moisture at maturity than PHM57. PHK46 is later with higher ear placement and flowers (GDU SHD and GDU SLK) earlier than PHM57. Root lodging, common smut, gray leaf spot, and southern corn leaf blight resistance is better for PHK46 but it is more susceptible to stalk lodging, ear mold, Stewart's wilt, and first brood European corn borer than PHM57.

Table 3E results show PHK46 yields more, has lower test weight, and higher grain harvest moisture than PHP60. PHK46 and PHP60 are similar in height and time of flowering (GDU SHD and GDU SLK). Seedling vigor is significantly better but early stand count is slightly lower for PHK46 than PHP60. PHK46 shows better resistance to root lodging and several agronomically important diseases but is more susceptible to stalk lodging and ear mold than PHP60.

Table 3F compares PHK46 to the line PHJ31/PHM57. PHK46 is shorter with lower ear placement and flowers (GDU SHD and GDU SLK) earlier than PHJ31/PHM57. PHK46 has better root lodging, common rust, and southern corn leaf blight resistance but is more susceptible to ear mold, Stewart's wilt, and first brood European corn borer than PHJ31/PHM57.

The results in Table 4 compare PHK46 to PHP60 crossed to the same inbred testers. The PHK46 hybrids have lower yield, test weight, and grain harvest moisture than the PHP60 hybrids. PHK46 hybrids have better seedling vigor and establish better early stands than PHP60 hybrids. Stalk and root lodging resistance is better for the PHK46 hybrids than the PHP60 hybrids.

                                      TABLE 3A                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                  __________________________________________________________________________                       YLD  EAR BAR PLT EAR SDG EST TIL GDU                                       VAR SC   SZ  PLT HT  HT  VGR CNT LER SHD                         YEAR    REGION                                                                               #   ABS  ABS ABS ABS ABS ABS ABS ABS ABS                         __________________________________________________________________________     TOTAL SUM     1   5.7  5.3 95.7                                                                               78.8                                                                               33.0                                                                               4.5 21.0                                                                               0.0 160.2                                     2   5.3  5.0 100.0                                                                              82.8                                                                               32.3                                                                               3.0 12.0                                                                               16.7                                                                               166.0                                     LOCS                                                                               3    4   1   4   4   2   1   1   6                                         DIFF                                                                               0.3  0.3 4.3 4.0 0.8 1.5 9.0 16.7                                                                               5.8                                       PROB                                                                               .742 .718    .156                                                                               .783                                                                               .205        .013+                       __________________________________________________________________________                       GDU  TAS TEX SCT STA RT  COM EAR SLF                                       VAR SLK  SZ  EAR GRN GRN LDG RST MLD BLT                         YEAR    REGION                                                                               #   ABS  ABS ABS ABS ABS ABS ABS ABS ABS                         __________________________________________________________________________     TOTAL SUM     1   163.0                                                                               5.0 5.7 6.5 6.4 100.0                                                                              7.0 4.0 7.5                                       2   170.0                                                                               8.3 8.0 7.0 6.8 31.6                                                                               3.7 7.3 6.0                                       LOCS                                                                               6    3   3   4   5   1   3   4   2                                         DIFF                                                                               7.0  3.3 2.3 0.5 0.4 68.4                                                                               3.3 3.3 1.5                                       PROB                                                                               .031+                                                                               .063*                                                                              .020+                                                                              .495                                                                               .587    .010+                                                                              .061*                                                                              .205                        __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PHG65                                                              * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 3B                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                  __________________________________________________________________________                       YLD                                                                               EAR BAR PLT EAR SDG EST TIL                                                                               GDU  GDU  POL                                VAR SC SZ  PLT HT  HT  VGR CNT LER                                                                               SHD  SLK  SC                   YEAR    REGION                                                                               #   ABS                                                                               ABS ABS ABS ABS ABS ABS ABS                                                                               ABS  ABS  ABS                  __________________________________________________________________________     TOTAL SUM     1   5.5                                                                               4.5 95.7                                                                               90.0                                                                               30.0                                                                               3.6 25.3                                                                               0.0                                                                               163.2                                                                               164.6                                                                               4.7                                2   3.5                                                                               4.5 100.0                                                                              72.0                                                                               24.0                                                                               5.4 28.5                                                                               0.0                                                                               134.1                                                                               134.9                                                                               7.0                                LOCS                                                                               2  2   1   1   1   5   4   2  10   9    3                                  DIFF                                                                               2.0                                                                               0.0 4.3 18.0                                                                               6.0 1.8 3.3 0.0                                                                               29.1 29.7 2.3                                PROB                                                                               .295                                                                              .000#           .037+                                                                              .279                                                                               1.00                                                                              .000#                                                                               .000#                                                                               .073*                __________________________________________________________________________                       TAS                                                                               TAS TEX SCT STA COM EAR GLF                                                                               SLF  STW  ECB                                VAR BLS                                                                               SZ  EAR GRN GRN RST MLD SPT                                                                               BLT  WLT  1LF                  YEAR    REGION                                                                               #   ABS                                                                               ABS ABS ABS ABS ABS ABS ABS                                                                               ABS  ABS  ABS                  __________________________________________________________________________     TOTAL SUM     1   9.0                                                                               4.3 4.3 4.0 6.0 6.0 4.5 7.5                                                                               7.0  6.0  6.0                                2   7.0                                                                               6.8 3.0 2.5 2.0 7.0 2.0 1.5                                                                               4.0  6.0  4.0                                LOCS                                                                               1  4   3   2   2   1   2   1  1    1    1                                  DIFF                                                                               2.0                                                                               2.5 1.3 1.5 4.0 1.0 2.5 6.0                                                                               3.0  0.0  2.0                                PROB   .030+                                                                              .057*                                                                              .205                                                                               .000#   .126                                  __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PH207                                                              * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 3C                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                                 BU  BU  YLD     EAR                                                                               BAR PLT EAR SDG EST TIL GDU                             VAR ACR ACR SC  MST SZ PLT HT  HT  VGR CNT LER SHD                  YEAR REGION                                                                               #   ABS % MN                                                                               ABS ABS ABS                                                                               ABS ABS ABS ABS ABS ABS ABS                  __________________________________________________________________________     TOTAL      1   93.5                                                                               136 5.8 23.4                                                                               5.2                                                                               97.8                                                                               78.8                                                                               33.0                                                                               4.7 31.7                                                                               20.9                                                                               160.4                SUM        2   57.6                                                                               86  5.5 30.5                                                                               5.8                                                                               100.0                                                                              78.3                                                                               27.0                                                                               4.5 37.1                                                                               0.0 164.0                           LOCS                                                                               2   2   4   2   5  2   4   4   8   7   5   11                              DIFF                                                                               36.0                                                                               51  0.3 7.1 0.6                                                                               2.2 0.5 6.0 0.2 5.4 20.9                                                                               3.6                             PROB                                                                               .279                                                                               .231                                                                               .789                                                                               .058*                                                                              .374                                                                              .500                                                                               .888                                                                               .069*                                                                              .795                                                                               .199                                                                               .374                                                                               0.37+                __________________________________________________________________________                    GDU  POL                                                                               TAS TEX TST SCT STA RT  COM EAR SLF ECB                            VAR SLK  SC SZ  EAR WT  GRN GRN LDG RST MLD BLT 1LF                 YEAR REGION                                                                               #   ABS  ABS                                                                               ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS                 __________________________________________________________________________     TOTAL      1   162.8                                                                               5.0                                                                               5.0 5.2 55.6                                                                               6.0 6.3 100.0                                                                              7.0 4.2 7.5 6.5                 SUM        2   170.2                                                                               6.5                                                                               6.7 7.2 52.2                                                                               5.6 6.3 71.4                                                                               2.3 6.2 5.5 7.5                            LOCS                                                                               9    4  6   5   2   5   6   1   3   5   2   2                              DIFF                                                                               7.4  1.5                                                                               1.7 2.0 3.5 0.4 0.0 28.6                                                                               4.7 2.0 2.0 1.0                            PROB                                                                               .005#                                                                               .182                                                                              .020+                                                                              .022+                                                                              .320                                                                               .587                                                                               .000#   .005#                                                                              .220                                                                               .000#                                                                              .000#               __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PHJ31                                                              * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 3D                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                  __________________________________________________________________________                       BU   BU   YLD       EAR                                                                               BAR PLT  EAR  SDG EST                               VAR ACR  ACR  SC   MST  SZ PLT HT   HT   VGR CNT                 YEAR    REGION                                                                               #   ABS  % MN ABS  ABS  ABS                                                                               ABS ABS  ABS  ABS ABS                 __________________________________________________________________________     TOTAL SUM     1   78.2 108  5.1  21.1 4.7                                                                               94.3                                                                               85.5 33.0 4.9 38.3                              2   68.2 94   4.4  18.9 5.0                                                                               94.9                                                                               77.9 30.8 4.7 40.4                              LOCS                                                                               8    8    7    8    6  7   8    8    19  17                                DIFF                                                                               10.0 14   0.7  2.2  0.3                                                                               0.7 7.6  2.3  0.2 2.2                               PROB                                                                               .046+                                                                               .041+                                                                               .283 .085*                                                                               .638                                                                              .661                                                                               .004#                                                                               .041+                                                                               .683                                                                               .346                __________________________________________________________________________                       DRP  TIL  GDU  GDU  POL                                                                               TAS TEX  TST  GRN SCT                               VAR EAR  LER  SHD  SLK  SC SZ  EAR  WT   QUL GRN                 YEAR    REGION                                                                               #   ABS  ABS  ABS  ABS  ABS                                                                               ABS ABS  ABS  ABS ABS                 __________________________________________________________________________     TOTAL SUM     1   96.5 20.9 163.4                                                                               167.2                                                                               5.0                                                                               4.9 5.3  57.0 7.0 5.3                               2   98.0 16.4 168.7                                                                               170.5                                                                               5.2                                                                               5.8 6.7  58.2 8.5 4.5                               LOCS                                                                               2    5    22   22   5  10  6    8    2   6                                 DIFF                                                                               1.5  4.5  5.3  3.3  0.2                                                                               0.9 1.3  1.2  1.5 0.8                               PROB                                                                               .739 .868 .000#                                                                               .010+                                                                               .861                                                                              .068*                                                                              .043+                                                                               .048+                                                                               .000#                                                                              .341                __________________________________________________________________________                                 STA STK RT  COM EAR GLF                                                                               SLF STW ECB                                         VAR GRN LDG LDG RST MLD SPT                                                                               BLT WLT 1LF                           YEAR    REGION                                                                               #   ABS ABS ABS ABS ABS ABS                                                                               ABS ABS ABS                 __________________________________________________________________________               TOTAL SUM     1   6.6 93.8                                                                               99.2                                                                               6.8 4.6 7.5                                                                               7.5 6.0 6.3                                         2   6.7 96.0                                                                               98.0                                                                               5.3 6.0 4.0                                                                               5.5 8.0 7.7                                         LOCS                                                                               13  4   4   4   7   1  2   1   3                                           DIFF                                                                               0.1 2.2 1.2 1.5 1.4 3.5                                                                               2.0 2.0 1.3                                         PROB                                                                               .874                                                                               .650                                                                               .524                                                                               .245                                                                               .094*  .000#   .057*               __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PHM57                                                              * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 3E                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                  __________________________________________________________________________                       BU  BU   YLD     EAR  BAR  PLT EAR SDG  EST                                VAR ACR ACR  SC  MST SZ   PLT  HT  HT  VGR  CNT                  YEAR    REGION                                                                               #   ABS % MN ABS ABS ABS  ABS  ABS ABS ABS  ABS                  __________________________________________________________________________     TOTAL SUM     1   76.5                                                                               110  5.3 23.5                                                                               4.8  94.8 83.4                                                                               31.3                                                                               4.8  40.3                               2   70.9                                                                               98   5.5 21.5                                                                               5.9  87.6 84.9                                                                               31.5                                                                               3.8  41.8                               LOCS                                                                               15  15   13  15  11   9    13  13  30   29                                 DIFF                                                                               5.6 12   0.2 2.0 1.1  7.2  1.5 0.2 1.0  1.5                                PROB                                                                               .357                                                                               .314 .753                                                                               .056*                                                                              .031+                                                                               .012+                                                                               .678                                                                               .934                                                                               .002#                                                                               .351                 __________________________________________________________________________                       DRP TIL GDU GDU POL TAS TEX  TST GRN SCT STA                               VAR EAR LER SHD SLK SC  SZ  EAR  WT  QUL GRN GRN                 YEAR    REGION                                                                               #   ABS ABS ABS ABS ABS ABS ABS  ABS ABS ABS ABS                 __________________________________________________________________________     TOTAL SUM     1   96.6                                                                               17.6                                                                               162.0                                                                              165.8                                                                              5.4 5.0 5.0  55.9                                                                               7.0 5.3 6.7                               2   100.0                                                                              21.0                                                                               161.4                                                                              166.2                                                                              5.3 4.6 7.3  56.9                                                                               8.0 5.9 6.3                               LOCS                                                                               2   6   34  34  7   17  8    15  2   12  22                                DIFF                                                                               3.4 3.4 0.6 0.4 0.1 0.4 2.3  1.0 1.0 0.5 0.5                               PROB                                                                               .282                                                                               .592                                                                               .502                                                                               .696                                                                               .838                                                                               .300                                                                               .001#                                                                               .124                                                                               .295                                                                               .356                                                                               .362                __________________________________________________________________________                              STK RT  BRT COM EAR GLF                                                                               SLF STW ECB ECB                                     VAR LDG LDG STK RST MLD SPT                                                                               BLT WLT 1LF 2SC                       YEAR    REGION                                                                               #   ABS ABS ABS ABS ABS ABS                                                                               ABS ABS ABS ABS                __________________________________________________________________________            TOTAL SUM     1   94.4                                                                               97.8                                                                               87.0                                                                               6.8 4.8 7.5                                                                               7.5 6.0 6.3 6.0                                     2   96.3                                                                               81.3                                                                               86.4                                                                               4.0 5.8 5.0                                                                               6.0 6.0 3.2 5.0                                     LOCS                                                                               6   6   2   4   10  1  4   1   6   1                                       DIFF                                                                               1.9 16.5                                                                               0.6 2.8 1.0 2.5                                                                               1.5 0.0 3.2 1.0                                     PROB                                                                               .297                                                                               .085*                                                                              .941                                                                               .022+                                                                              .074*                                                                              0.58*  .000#                      __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PHP60                                                              * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 3F                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                  __________________________________________________________________________                   BU  BU  YLD     EAR PLT EAR SDG EST TIL GDU GDU                            VAR ACR ACR SC  MST SZ  HT  HT  VGR CNT LER AHD SLK                  YEAR                                                                               REGION                                                                               #   ABS % MN                                                                               ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS                  __________________________________________________________________________     TOTAL     1   27.5                                                                               74  6.0 24.0                                                                               5.5 81.8                                                                               30.0                                                                               4.9 32.5                                                                               34.8                                                                               159.1                                                                              163.4                SUM       2   48.6                                                                               127 8.0 27.6                                                                               8.5 92.5                                                                               33.3                                                                               6.3 34.8                                                                               9.1 160.2                                                                              165.5                          LOCS                                                                               2   2   6   2   6   4   4   8   7   3   15  16                             DIFF                                                                               21.1                                                                               53  2.0 3.6 3.0 10.8                                                                               3.3 1.4 2.3 25.8                                                                               1.1 2.1                            PROB                                                                               .466                                                                               .461                                                                               .067*                                                                              .141                                                                               .012+                                                                              .075*                                                                              .391                                                                               .092*                                                                              .399                                                                               .515                                                                               .292                                                                               .093*                __________________________________________________________________________                   POL TAS  TEX TST SCT STA RT  COM EAR SLF SRW ECB                           VAR SHD SLK  SC  SZ  EAR WT  GRN GRN LDG RST                         YEAR                                                                               REGION                                                                               #   ABS ABS  ABS ABS ABS ABS ABS ABS ABS ABS                         __________________________________________________________________________     TOTAL     1   5.0 4.7  4.8 55.4                                                                               6.0 6.5 100.0                                                                              7.0 4.2 8.0 6.0 6.0                 SUM       2   8.3 7.3  7.3 54.8                                                                               6.8 8.6 81.8                                                                               4.7 8.3 7.0 8.0 7.5                           LOCS                                                                               4   10   6   2   6   9   1   3   6   1   1   2                             DIFF                                                                               3.3 2.5  2.5 0.6 0.8 2.1 18.2                                                                               2.3 4.2 1.0 2.0 1.5                           PROB                                                                               .099*                                                                              .001#                                                                               .002#                                                                              .693                                                                               .402                                                                               .014+   .020+                                                                              .000#       .555                __________________________________________________________________________      VARIETY #1  PHK46                                                              VARIETY #2  PHJ31/PHM57                                                        * = 10% SIG                                                                    + = 5% SIG                                                                     # = 1% SIG                                                               

                                      TABLE 4                                      __________________________________________________________________________     AVERAGE INBRED BY TESTER PERFORMANCE COMPARING PHK46 TO PHP60                  CROSSED TO THE SAME INBRED TESTERS AND GROWN IN THE SAME EX-                   PERIMENTS. ALL VALUES ARE EXPRESSED AS PERCENT OF THE EXPERIMENT               MEAN EXCEPT PREDICTED RM, SELECTION INDEX, AND YIELD (BU/AC).                  __________________________________________________________________________                      SEL BU         GDU STK RT                                            INBRED                                                                               PRM IND ACR YLD MST                                                                               SHD LDG LDG                                    __________________________________________________________________________     TOTAL  REPLIC.                                                                               13  15  15 15  15  2  14   8                                     MEAN WTS                                                                              PHK46 125 101 129 98  99 97  107 74                                     MEAN WTS                                                                              PHP60 121 104 135 102 96 98  91  99                                            DIFF.  4   3   5   4   3  1  17  25                                     __________________________________________________________________________                  STA TST GRN SDG EST                                                                               STK PLT EAR                                           INBRED                                                                               GRN WTA QUL VGR CNT                                                                               CNT HT  HT                                     __________________________________________________________________________     TOTAL  REPLIC.                                                                               14  15  16  4   4  16  6  6                                      MEAN WTS                                                                              PHK46 107 100 104 134 108                                                                               101 101 99                                     MEAN WTS                                                                              PHP60 104 104 121 104 101                                                                               104 101 101                                           DIFF   3   4   16  30  7  2   0  2                                      __________________________________________________________________________

DEPOSITS

Applicant has made a deposit of at least 2,500 seeds of inbred corn line PHK46 with the American Type Cultural Collection (ATCC), Rockville, Md. 20852 U.S.A., ATCC Deposit No. 97078. The seeds, deposited with the ATCC on Mar. 8, 1995, were taken from the deposit maintained by Pioneer Hi-Bred International, Inc., 700 Capital Square, 400 Locust Street, Des Moines, Iowa 50309-2340 since prior to the filing date of this application. This Deposit of the Inbred corn line PHK46 will be maintained in the ATCC Depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the enforceable life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period. Additionally, Applicant has satisfied all the requirements of 37 C.F.R. 1.801-1.809, including providing an indication of the viability of the sample. Applicant imposes no restrictions on the availability of the deposited material from the ATCC; however, Applicant has no authority to waive any restrictions imposed by law in the transfer of biological material or its transportation in commerce. Applicant does not waive any infringement of its rights granted under this patent or under the Plant Variety Protection Act (7 U.S.C. 2321 et seq.). PHK46 is a U.S. Protected Variety under Plant Variety Protection Certificate No. 9000246. 

What is claimed is:
 1. Inbred corn seed designated PHK46, having the ATCC Accession No.
 97078. 2. A corn plant, and its parts, produced by the seed of corn plant PHK46, the seed of which have been deposited under ATCC Accession No.
 97078. 3. A tissue culture of regenerable cells of corn plant PHK46 the seed of which have been deposited under ATCC Accession No.
 97078. 4. Tissue culture of corn plant PHK46, the seed of which have been deposited under ATCC Accessi. On No. 97078, comprising regenerable cells of a plants part selected from the group consisting of roots, root tips, silk, flowers, kernels, ears, cobs, husks, stalks, meristematic tissue, anthers, leaves, embryos, pollen, and cells and protoplasts thereof.
 5. An inbred corn plant having all the physiological and morphological characteristics of the plant named PHK46, the seed of which have been deposited under ATCC Accession No.
 97078. 6. A corn plant, and its parts, regenerated from the regenerable cells of claim 4, the regenerated corn plant possessing all the physiological and morphological characteristics of corn plant PHK46, the seed of which have been deposited under ATCC Accession No.
 97078. 7. A method for producing first generation (F₁) hybrid corn seed comprising crossing a first inbred parent corn plant with a second inbred parent corn plant and harvesting the resultant first generation (F₁) hybrid corn seed, wherein said first or second parent corn plant is the corn plant named PHK46, the seed of which have been deposited under ATCC Accession No.
 97078. 8. The method of claim 7 wherein inbred corn plant PHK46, the seed of which have been deposited under ATCC Accession No. 97078, is the female parent.
 9. The method of claim 7 wherein inbred corn plant PHK46, the seed of which have been deposited under ATCC Accession No. 97078, is the male parent.
 10. An F₁ hybrid seed and plant, and its parts, grown therefrom produced by the method of claim
 7. 